• “Signal K https://signalk.org is a modern and open data format for marine use. Built on standard web technologies including JSON, WebSockets and HTTP, Signal K provides a method for sharing information in a way that is friendly to WiFi, cellphones, tablets and the Internet.”

In these pages you can find information which helps you to connect OpenCPN with a Signal K data format enabled servers. We collect information references, and/or explain details when no external source is available related to Signal K and OpenCPN, such as

• Readily available Signal K enabled systems
• Installation of your own Signal K server (Windows/Mac and Raspberry Pi/Linux)
• Configuration of the Signal K server in view of its usage with OpenCPN
• Technical information (not mandatory reading)

Read and use SignalK -Cruiser Forum Thread

See this Cruisers Forum Thread “read and use signalK data”

See Filter NMEA/Course and Speed not working

After a day with extensive testing, the golden rule when not all active plugins can read Signal K natively: First:

1. If ONE NMEA 0183 needs to be generated from Signal K / NMEA 2000 code, then ALL used signals should be converted into NMEA 0183 format and the direct reading of Signal K data should be deactivated.
   1. Note: A signal that is available thru BOTH NMEA 0183 and Signal K may cause problems. Some signals may be ok but others may cause problems and there is no readily apparent way to select/limit which signals to convert directly. Better safe than sorry. Also be aware that perhaps not all wanted sentences can be generated as NMEA 0183.
2. If your GPS delivers more that one RMC sentence (eventually converted form NMEA 2000 into NMEA 0183) then multiply the setting 'Filter NMEA Course and Speed data' with the number of sentences per second. That is, of course, if you use that setting at all.

1. I installed SignalK on a Raspberry. This Raspberry is directly connected with Tinypilot as the server. On the Raspberry I connected a GPS receiver with an USB connection. That is all working well and I see in SignalK the data coming in, from the Tinypilot (compass) and from the GPS receiver (satellite).
2. On a tablet I installed OpenCPN with a Netwerk connection to SignalK/ Network/ IPadress of the Raspberry/Network port 3000. If I use the NMEA debugging of OpenCPN, I don't see any data coming in or going out. Also no GPS or Compass connection.
3. My question: A SignalK connection from OpenCPN on the tablet, can I normally see data that is coming in with NMEA0183 (what I expect with debugging)? Or is there a special reason for no connection between SignalK and OpenCPN?

1. Protocol: NMEA0183 and Signal K data are two different data formats.
2. SignalK data can't be seen in “NMEA Debug window”
3. If you want NMEA0183 from SignalK(SK) you have to use protocol TCP and port 10110.
4. If you want SignalK data from SK you have to use protocol Signal K and port 3000. (Please disable “Automatic server discovery” once used.)
5. The connection between OCPN and SK works fine if the tablet and Raspberry are both connected to the same IP network segment. (Like e.g. 192.168.1.xxx)

What is missing is how to install SignalK server on exsisting Linux system: At first you need to install NPM (nodejs):

sudo install npm.

Then the installation of SignalK:

sudo npm install -g --unsafe-perm signalk-server

Then must set the SignalK server to start:

sudo signalk-server-setup

Most of the items are: no

• Then the signalK server starts at the starting of the system.
• SignalK is HTML and the dashboardSK can be used in every browser: localhost: 3000
• Or from a remote system: ipadres signalk server: Ip:3000
• In OpenCPN you can use the signalk direct with: network localhost: signalk and port: 3000
• From a remote server change localhost to ipadres of the server computer.
• Windows install is also possible but not with the above procedure.

How you connect the others to the server? I connect mine through wired ethernet and a router, but wifi would work well and the Pi can be set up as a wireless access point, so you can connect extra Pis to that one pi via wifi.